1. Field of the Invention
This invention relates generally to improvements in forming articles from blank stock and, more particularly, to a new and improved system and method for bulge forming a substantially flat blank into an article which comprises a formed part, and which includes a shaped portion.
2. Description of the Related Art
It has been known to form an article such as a metal article including a shaped portion from blank metal stock through various processes such as roll forming, stretch forming, spinning, or hydroforming, augmented by straightening, repeated inspections, and finishing operations.
However, such metal forming processes require a number of forming operations, resulting in variations in metal thickness, residuals, induced stress, inconsistency, and relatively low article integrity, and further requiring extensive finishing operations to form a finished part. These problems are particularly prevalent in the metal forming of very large, lightweight, structural modules, such as for aircraft structures.
Therefore, those concerned with the development and use of improved metal forming systems and methods and the like have recognized the need for improved systems and methods for forming a substantially flat sheet metal blank, of any size, shape, and thickness, into an article which comprises a finished formed part, and which includes a shaped portion or a plurality of shaped portions, in an efficient and effective manner. The need has further been recognized for such systems and methods which prevent thickness variations and scratches, improve finished part integrity and consistency, reduce the number of process operations, and prevent induced stress. The need for such effective and efficient metal forming has been particularly recognized for processes for the metal forming of large, thin-walled, lightweight, complex-shaped, structural, finished parts, for industries such as the aircraft and defense industries.
Accordingly, the present invention fulfills these needs by providing efficient and effective systems and methods for metal forming a sheet metal blank into an article of any size, shape, and thickness which includes a shaped portions, while providing improved article thickness uniformity, integrity and consistency, with a reduced number of operations, and which greatly reduces induced stress.
Briefly, and in general terms, the present invention provides a new and improved system and method for bulge forming an article from blank stock, in an effective and efficient manner.
By way of example, and not by way of limitation, the present invention provides a new and improved system for bulge forming a substantially flat blank into an article which comprises a formed part and which includes shaped portions.
More particularly, the bulge forming system of the present invention may include a form-shaping element, for enabling the shaped portions of the article to be formed thereagainst. It includes a portion complementary in shape to the shape of the shaped portion of the article to be formed thereby. It may further include an enclosure enabling element for enabling the form-shaping element to be enclosed therein, and for enabling the blank to be positioned and enclosed therein.
The system, in accordance with the present invention, may further include a flexible member, adapted to be enclosed within the enclosing enabling element, and adapted to bulge within the enclosing enabling element upon the application of pressure to the flexible member. The flexible member may also be adapted to exert pressure by pushing on the blank adapted to be positioned in the enclosing enabling element, and to bend the blank relative to the form shaping element complementary portion to form the shaped portion of the article. The system may also include an expansion enabling element for enabling expansion of the flexible member, upon pumping a pressure exerting medium therethrough into the flexible member, so as to exert pressure on the blank and form the shaped portion of the article against the form-shaping element.
Therefore an advantage of the present invention is that it includes an improved system and method for effectively and efficiently bulge forming substantially flat blank stock into an article which may comprise a formed finished part, which includes a shaped portion, or a complex part which includes a plurality of shaped portions.
A further advantage is that the present invention provides the bulge forming of a formed finished part of any size, shape, and thickness which reduces the number of process steps, reduces induced stress and scratches in the article, and improves the thickness uniformity, integrity and consistency of the finished part.
These and other objects and advantages of the invention will become apparent from the following more detailed description, when taken in conjunction with the accompanying drawings of illustrative embodiments.